//
// Created by wze-zero on 2024/9/3 003.
//
#include <iostream>

using namespace std;

int main() {
    int num, max = -32768;
    for (int i = 0; i < 4; ++i) {
        cin >> num;
        max = max < num ? num : max;
    }
    cout << max << endl;
    return 0;
}